The sauna design rabbit hole is a very deep one.
If anyone is interested in more information about sauna design in general, Trumpkin's Notes are by far the most referred to guide out there. [1]
There are also new products [2] which help improve saunas which are not ideally designed or where there are constraints (ceiling height mostly) to deal with.
1: https://localmile.org/trumpkins-notes-on-building-a-sauna/ 2: https://saunum.com/en/
I am actually typing this from a sauna with less than ideal ventilation (slightly ajar glass door) - need to cut vent holes to the sauna/house walls but haven’t gotten around to it - so the timing is good. The main use of the ventilation is to not end up with too high CO2 concentration
Wouldn't it be more practical to have a prominent CO2 monitor and only exchange the air (maybe by opening the door for a few seconds) if it CO2 gets too high ?
Maybe it's hard keeping a co2 monitor operating in humid sauna conditions, I dunno.
Also, given that many saunas are not airtight, I wonder what a steady state CO2 concentration would be. It may be high, but not dangerous.
Some additional discussion on Reddit https://www.reddit.com/r/Sauna/comments/1b2skn6/a_45_year_en...
Am I reading this right? Is there no heat exchanger in the ventilation? That seems like an obvious improvement.
Off-topic but I've been curious: how well do phones handle saunas? I thought the heat and moisture would pretty much be the worst environment for electronics. Is that not the case?
Thought it would be about heat exchangers.
I have not noticed any venting in the sauna at my gym, but perhaps it's not obvious. It's a pretty big sauna, it will easily seat over a dozen people and people are coming in and out often enough that the door opening probably provides adequate air exchange.
Why is the age of any relevance here?
tldr: place air inlet above the heat (B); air outlet on the other side at the floor (D). See figure: https://www.saunatimes.com/wp-content/uploads/IMG_6556-1-560...
This ensures: 1) quick heat up of fresh air 2) vertically uniform heat 3) creation of better steam
I enjoy reading articles (even if this one felt like it had been translated slightly clumsily) where scientific rigor has been applied to something mundane.
I've gained an understanding, at least.